Update module build options to match with GENERIC kernel options

Include the SYSV_* entries for modular procfs

branches: 1.7.26; 1.7.32;
Kill WARNS = 3

Add the limit node

Bump default value of WARNS for modules from 3 to 5, and
explicitly set WARNS for modules that fail with WARNS=5.

Also, turn on -Wno-missing-noreturn for clang for some files.

At the moment, among ~ 360 modules,
- 2 (lua and zfs) need WARNS=0
- 1 (solaris) needs WARNS=1
- 136 need WARNS=3 (mostly due to sign-compare)
- 4 need WARNS=4
- others can be compiled with WARNS=5

Discussed on tech-kern.

branches: 1.4.4;
Remove the filesystem tracing feature

This is a legacy interface from 4.4BSD, and it was
introduced to overcome shortcomings of ptrace(2) at that time, which are
no longer relevant (performance). Today /proc/#/ctl offers a narrow
subset of ptrace(2) commands and is not applicable for modern
applications use beyond simplistic tracing scenarios.

This removal will simplify kernel internals. Users will still be able to
use all the other /proc files.

This change won't affect other procfs files neither Linux compat
features within mount_procfs(8). /proc/#/ctl isn't available on Linux.

Remove:
- /proc/#/ctl from mount_procfs(8)
- P_FSTRACE note from the documentation of ps(1)
- /proc/#/ctl and filesystem tracing documentation from mount_procfs(8)
- KAUTH_REQ_PROCESS_PROCFS_CTL documentation from kauth(9)
- source code file miscfs/procfs/procfs_ctl.c
- PFSctl and procfs_doctl() from sys/miscfs/procfs/procfs.h
- KAUTH_REQ_PROCESS_PROCFS_CTL from sys/sys/kauth.h
- PSL_FSTRACE (0x00010000) from sys/sys/proc.h
- P_FSTRACE (0x00010000) from sys/sys/sysctl.h

Reduce code complexity after removal of this functionality.

Update TODO.ptrace accordingly: remove two entries about /proc tracing.

Do not keep legacy notes as comments in the headers about removed
PSL_FSTRACE / P_FSTRACE, as this interface had little number of users
(close or equal to zero).

Proposed on tech-kern@.

All filesystem tracing utility users are encouraged to switch to ptrace(2).

Sponsored by <The NetBSD Foundation>

branches: 1.3.6;
Add auxv

branches: 1.2.18; 1.2.36; 1.2.40; 1.2.44;
Sync procfs module with kernel change for x86 MD.

branches: 1.1.2; 1.1.4; 1.1.8; 1.1.20; 1.1.24; 1.1.26;
Add of bunch of file system modules.